Sharpening apparatus for eccentric involute slicing blades



March 20, 1956 w. LUST 2,738,628

SHARPENING APPARATUS FOR ECCENTRIC INVOLUTE SLICING BLADES Filed June 28, 1955 2 Sheets-Sheet l I I HHJ ,f

5 11"- Iml 1.... I, 3 54 Z5 Z1 ATTORNEYS W. LUST March 20, 19 56 SHARPENING APPARATUS FOR ECCENTRIC INVOLUTE SLICING BLADES 2 Sheets-Sheet 2 Filed June 28, 1955 Zus/ INVENTOR fi illzam [fin-4 y-1.84M V K ATTORN EYS United States Patent SHARPENING APPARATUS FOR ECCENTRIC INVOLUTE SLICING BLADES William Lust, Albany, N. Y. Application June 28, 1955, Serial No. 518,611 4 Claims. (Cl. 51-247) This invention relates to improved sharpening apparatus for slicing blades having eccentric involute cutting edges.

Slicing machines are sometimes provided with slicing blades having an eccentric involute cutting edge. The slicing blade is continuously rotated and the product to be sliced is continuously fed to one side of the blade. Due to the eccentric involute curvature of the cutting edge each rotation of the blade produces one slice of the product. Blades of this type are very satisfactory since they cause a continuous slicing of the product. However, due to the unusual curvature of the edge portion the sharpening of the blade presents difliculties. Thus, it is difiicult to obtain uniform sharpening of all portions of the blade and to preserve the same involute curvature and the same pitch or angle to the surfaces of the blade.

It is an object of the present invention to overcome the difiiculties heretofore encountered and to provide improved simplified apparatus for sharpening a slicing blade having an involute cutting edge whereby uniform sharpening can be obtained and the same involute curvature and the same angle or pitch of the surfaces can be maintained throughout the blade.

A further object is the provision of improved apparatus of the above character of relatively inexpensive construction which is simple to manufacture, assemble and use and which is rugged and sturdy so that it maybe used over a long period of time with comparative freedom from wear.

In the accompanying drawings:

Fig. 1 is a top plan view of an eccentric involute slicing blade having sharpening apparatus embodying my invention assembled therewith;

Fig. 2 is a front elevational view of the slicing blade and sharpening apparatus;

Fig. 3 is a detailed front elevational view of the central portion of the blade and apparatus showing the mounting center and evolute;

Fig. 4 is a cross-sectional view in the direction of the arrows on the line 4-4 of Fig. 3;

Fig. 5 is a detailed view in perspective of a segment of the blade and showing one form of hand operated sharpener which may be used with my apparatus;

Fig. 6 is a cross-sectional view in the direction of the arrows on the line 6-6 of Fig. 5;

Fig. 7 is a top plan view similar to Fig. 1 of an eccentric involute slicing blade showing a modified form of sharpening apparatus embodying my invention; and

Fig. 8 is a front elevational view of the slicing blade and apparatus shown in Fig. 7.

My improved sharpening apparatus is particularly useful in sharpening slicing blades of the eccentric involute type. Thus, in the accompanying drawings 1 have shown a slicing blade 10 having a peripheral involute cutting edge 11. The blade is provided with an opening in the usual manner to accommodate the mounting shaft 12. Fixed to the shaft 12 is the hub and mounting disk 13 and 14 with the disk engaging the inner face of the central 2,738,628 Patented Mar. 20, 1956 portion of the slicing blade. Removably disposed on the shaft on the opposite side of the blade is the hub and mounting disk 15 and 16. The disks 14 and 16 as well as the blade 10 have apertures extending therethrough which accommodate the nuts and bolts 17. The outer or free end of the shaft 12 is threaded and a nut 18 is applied thereto to help to retain the slicing blade securely in place.

The shaft 12 and the mounting for the blade illustrated in the accompanying drawings is one conventional type of shaft and mounting employed on a slicing machine and my sharpening apparatus may be applied to the blade mounting of the slicing machine so that the blade can be sharpened while in the machine. If preferred, the blade may be removed from the machine and a separate shaft and mounting of the type illustrated may be provided for use with my sharpening apparatus.

My improved sharpening apparatus comprises generally an evolute for the involute cutting edge of the sharpening blade and a flexible member which may be partially wrapped around the evolute and having a tangent portion for supporting a sharpener so that it will follow the curvature of the cutting edge as the tangent portion is wrapped around the evolute.

For this purpose I provide a mounting and wrapping post in the form of the hollow cap 20 fitted over the nut 1 18 and having an outwardly projecting cylindrical portion 21 which serves as the wrapping post for the tangential member. The cap 20 may be held in place at the end of shaft 12 in any suitable manner as, for instance, by means of a machine screw 22 extending through the washer or disk 23 fitted into the outer end of the cap as shown. The

screw 22 engages in a threaded opening formed in the end of shaft 12.

Connected to the mounting post 21 is the tangent memher which preferably takes the form of a relatively thin elongated flexible tape 25. The inner end of the tape is fixedly connected to the mounting and wrapping post by being extended into the recess 26 and Wrapping around the pin 27 as shown most clearly in Figs. 3 and 4.

The circumference of the wrapping post 21 is preferably slightly smaller than the circumference of the true evolute of the involute cutting edge 11 and a portion of the flexible tape is wrapped around the wrapping post, as shown, until the desired circumference is obtained.

In order to provide a smooth wrappping surface without any sharp ridges or variations in circumference, the diameter of the wrapping post is slightly reduced in an involute curvature immediately adjacent the slot 26 in the direction in which the tape is wrapped, as shown at 28 in Fig. 3. In this connection, the total reduction in diameter at the point 28 should be approximately equal to the thickness of the tape and thereafter the diameter should gradually increase to the normal diameter of the wrapping post in the direction in which the tape is wound.

The portion of the tape beyond the evolute portion which is wrapped around the wrapping post is extended tangentially outwardly as shown and fixed to the tangent portion adjacent the peripheral sharpening edge of the blade is .a.suitable sharpener 30. In this connection the tape -should be extending tangentially outwardly at the portion of the blade having the greatest diameter, as shown in Fig. .2, and the sharpener should then be afiixed to the tangent portion at a position to engage with the cutting edge. Thus, when the blade is rotated in a counter-clockwise direction or the sharpener is rotated in a clockwise direction, as viewed in Fig. 2, the flexible tape will wrap around the evolute portion on the winding post 21 and the sharpener 30 will follow the involute curvature of the cutting edge. By arranging the diameter of the winding post so that the true evolute is obtained when a portion of the tape is wrapped around the winding post a degree of tolerance for variations in the size of the slicing blade is obtained.

Where the peripheral size of the blade is relatively larger a larger evolute can be obtained by wrapping a greater portion of the flexible tape around the winding post. Where the peripheral size of the cutting blade is relatively smaller a relatively smaller evolute can be obtained by wrapping a relatively shorter length of tape around the wrapping post.

Also, as the blade wears the amount of tape wrap ed around the winding post can be changed so as to accommodate the size and curvature of the evolute to the involute form of the cutting edge.

The particular type of sharpener employed may of course be varied. Thus, in Figs. 1 to 6 inclusive I have shown a manual sharpener having a clamp portion 31 in the form of two parallel plates through which the tape 25 may be extended and clamped in position at the desired location by means of the bolts 32 extending through the plates fitted with wingnuts 33. By loosening the wingnuts the clamping portion may be adjusted longitudinally with respect to the tape 25 to any desired position. When the desired position is obtained then the sharpener can be held firmly in place by tightening the wingnuts. Secured to the clamping portion is the sharpener head 34 having a finger grip or handle portion 35 and a suitable tool, such as the abrasive stone 36. The sharpener head 34 is disposed at the proper angle to the clamping portion 31 so that when the sharpener is clamped to the tape and extended laterally outwardly, as shown, the sharpening tool 36 will be disposed at the proper angle to impart the desired bevel to the cutting edge.

In using the manual sharpener the parts are assembled, as shown, and the tape is partially wrapped around the winding post to provide the proper size evolute. The remaining portion of the tape is then extended tangentially outwardly and the sharpener 3% is clamped in place so that the sharpening tool properly engages the involute cutting edge 11. The sharpening tool may then be operated to sharpen the edge and as the tape is wound around the evolute either by rotating the shaft 18 or by rotating the sharpener around the blade it will be appreciated that the sharpening tool will follow the involute curvature of the blade. As the blade wears from use the size of the evolute may be adjusted to reflect the reduced involute curvature by wrapping a lesser amount of the tape around the winding post.

Instead of the manual sharpener 30, I may employ a power or motor driven sharpener, as shown in Figs. 7 and 8. Thus, I have illustrated an electric motor 40 mounted on a suitable support 41 which, in turn, is provided with a clamp 42 similar to the clamp 31 which is cooper-able to clamp the flexible tape 25. The shaft of the motor is provided with a suitable sharpening wheel 43 and the clamp 42 and tape 25 are adjusted so that the sharpener wheel properly engages the cutting edge. It will be noted that the motor and sharpener wheel are disposed at an angle so as to impart the desired angle to the cutting edge. The base 41 is mounted on a bracket 44 which is pivotally mounted at 45 to the base structure 46 of the machine so that as the tape is wound around the evolute the arm 44, support 41, motor 40 and sharpening tool 43 can pivot inwardly to follow the involute curvature of the cutting edge 11. In using this form of my apparatus the motor 40 is set into operation and the blade 10 is rotated slowly in a counter-clockwise direction. As the tape 25 wraps around the evolute the sharp- 4 ening tool 43 will follow the curvature of the cutting edge 11.

It will thus be seen that I have provided improved sharpening apparatus for a slicing blade having an cecentric involute cutting edge and that my apparatus will serve to sharpen the edge in a uniform manner preserving the proper involute curvature and maintaining the proper pitch or angle to the edge.

It will also be seen that my apparatus is relatively simple to manufacture, assemble and use.

Modifications may of course be made in the illustrated and described embodiment of my invention without departing from the invention as set forth in the accompanying claims.

I claim:

1. Sharpening apparatus for a slicing blade of the type having a peripheral involute cutting edge comprising: means providing both a mounting center for supporting the slicing blade to be sharpened and also an evolute for said involute cutting edge; and a flexible tangent member connected to said evolute and being cooperable to wrap therearound and having a sharpener mounting portion for supporting a sharpener, said sharpener mounting portion being spaced from the evolute so that it follows the approximate curvature of the involute cutting edge of the blade to be sharpened as the said flexible tangent member is wrapped around the evolute.

2. Sharpening apparatus for a slicing blade of the type having a peripheral involute cutting edge comprising: means providing both a mounting center for supporting the slicing blade to be sharpened and also a wrapping post; and an elongated relatively thin flexible tape connected to the wrapping post and having a portion wrapped around the post to provide an evolute for said involute cutting edge of the slicing blade and also having a tangent portion extending outwardly therefrom which is cooperable to wrap around the evolute portion, said tangent portion having a sharpener mounting area spaced from the evolute portion so that it follows the approximate curvature of the involute cutting edge of the blade to be sharpened as the tangent portion is wrapped around the evolute portion.

3. Sharpening apparatus of the type set forth in claim 2 in which the thin flexible tape is connected to the wrapping post adjacent the inner end thereof and the periphery of the wrapping post at the point of connection is reduced in diameter by the approximate thickness of the tape and gradually increases in diameter in the direction in which the tape is wrapped around the post.

4. The combination with a slicing blade of the type having a peripheral involute cutting edge for sharpening apparatus which comprises means providing a mounting center supporting the slicing blade at the evolute center thereof and projecting outwardly beyond the slicing blade to provide a wrapping post, an elongated relatively thin flexible tape connected to said mounting post and having a portion partially wrapped around the wrapping post to provide an evolute for said involute cutting edge and also having a tangent portion projecting outwardly from said evolute portion and being cooperable to wrap around the evolute portion and a sharpener secured to said tangent portion a spaced distance from the evolute portion so that it follows the approximate curvature of the involute cutting edge of the blade as the tangent portion is wrapped around the evolute portion.

No references cited. 

